When it comes to romance, fruit flies don’t bring flowers or chocolates. Instead, some species woo potential mates by sharing a meal in the most unusual way possible: by regurgitating partially digested food straight into the female’s mouth.

To us, it sounds more like a dare than a declaration of love. But for the flies, it’s a calculated strategy. The regurgitated “gift” contains sugars, proteins, and other nutrients that can boost the female’s energy and, ultimately, her reproductive success. In evolutionary terms, it’s a clever move. A well-fed partner is more likely to choose a generous suitor, giving him a better chance of passing along his genes.

This behavior, known as “trophic regurgitation,” isn’t unique to fruit flies. Birds sometimes feed mates or chicks this way, and even certain insects and fish use food sharing as a form of bonding or investment in the future. In every case, the message is clear: “Stick with me—I’m a good provider.”

For fruit flies, the ritual turns the ordinary act of feeding into a test of commitment. A male willing to part with his own resources demonstrates that he has energy and stamina to spare. That’s exactly what a female needs to see before picking him as her mate.

Curious about another unusual courtship? See how the water boatman makes music beneath the surface. Read more here.